Dave Penman, general secretary of the FDA, the union that represents senior civil servants, has said that Boris Johnson must address reports that his chief aide Dominic Cummings broke lockdown rules.

It comes after the Mirror and the Guardian reported that the chief adviser travelled 260 miles during the lockdown at the end of March.

Mr Penman told the Today programme that “essentially, when he (Mr Cummings) says or does something he is doing it in the Prime Minister’s name”.

He added: “I think the Prime Minister needs to understand how heartbreaking this lockdown has been for so many families and the sacrifices that have been made up and down the country.

“I think in these circumstances, if it looks like there is one rule for those at the centre of Government and one rule for rest of the country, then really the Prime Minister has a responsibility, as well as a constitutional responsibility, to explain his actions.”